I have not yet uploaded them to YouTube because they're appearing squished in Quicktime (v7.6.0)

Let's see.

Computer is a MacBook Pro with Leopard v10.5.6
My Compressor version is v.3.0.5
Final Cut Pro version is v.6.0.5
My source codec is 1920x1080 Apple ProRes 422 Integer (Little Endian), with Timecode
My desired output is an H.264 fit for fast web streaming or something akin to such

And overall, I need it to keep it's 16:9 aspect ratio after compression.